1. Field of the Invention
The present invention is related to a radiation image detector that records radiation images when radiation is irradiated thereon.
2. Description of the Related Art
Various radiation image detectors, that record radiation images of subjects when radiation which has passed through the subjects is irradiated thereon, have been proposed and are currently in use.
A radiation image detector that utilizes semiconductor materials that generate charges is a type of the aforementioned radiation image detectors. Radiation image detectors of this type that employ an optical readout method and that employ a TFT readout method have been proposed (refer to Japanese Unexamined Patent Publication No. 2005-183670, U.S. Pat. No. 7,126,127 and U.S. Patent Application Publication No. 20060255239).
Radiation image detectors that employ a-Se as the semiconductor material have been proposed.
Faulty pixels is a problem that often occurs in radiation image detectors that employ a-Se. A factor that causes faulty pixels is crystallized selenium, which is interspersed within the a-Se semiconductor material. Accidental charge injection, having the crystallized selenium as its origin, causes excessively accumulation or excessive flow of charges within the radiation image detector, which in turn causes faulty pixels to be generated.
It has been discovered that the size of the crystallized selenium increases as irradiation of radiation onto the radiation image detectors and readout of image signals therefrom are repeated.
That is, the crystallized selenium that originates from a foreign particle or the like becomes larger as recording and readout of radiation images are repeated. This causes a problem that the enlargement of the crystallized selenium increases the occurrence of faulty pixels.